Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Heterobranchia Burmeister, 1837 [monotypic] see Superorder Heterobranchia Burmeister, 1837 Order Heterostropha Fischer, 1885 Superfamily Architectonicoidea Gray, 1850 Family Omalaxidae Cossmann, 1916 [monotypic] 1 Genus Omalaxis Deshayes, 1832